uwsgi-python/pretix: Update pip query for installation

https://pretix.eu/about/en/blog/20230426-release-4190/ → “Runtime and server
environment”

uwsgi-python/vars/pretix.yml

@@ -40,7 +40,7 @@ app_deploy_key: ''
 app_git_url: 'https://github.com/pretix/pretix.git'
 app_git_version: 'stable'  # release/2.4.x
 app_git_pip: true
-app_git_pip_query: '#egg=pretix&subdirectory=src'
+app_git_pip_query: '#egg=pretix'
 app_requirements_file: ''
 app_exectmp: true